IBM 7868-047 Modems

Ali cctalk at
Mon Nov 3 15:20:54 CST 2014

> If you want to use your modems on the PSTN, the first thing to check is
> whether they require a single pair connection between them or two
> pairs.  My ones have RJ11 type connectors which might give the
> impression that only a single pair is required but two of the pairs are
> actually used, one for transmit and the other for receive.


Not quite sure as how I would determine this. One of the questions I have is
if these modems support Hayes AT commands. In quick testing they do not seem
to (at least as configured). If they don't then they become pretty much
useless. If they at least support Hayes commands one could do further
testing and even set them up to be used locally (in house). I am surprised
no one has ever run across these guys. I may have to hit up Usenet and the
modem groups in there for some help

> It is also possible that your modems are synchronous only which will be
> a problem if you want to talk to asynchronous only modems.

The only information I have found is at the following link:

Namely: "There are two and four port models with fan-in/fan-out and/or data
multiplex functions for both synchronous and asynchronous data terminal
equipment to share the same link". I am guessing they can work


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